The lanthanum (La) extraction kinetics from chloride medium containing two complexing agents lactic acid (HLac) and citric acid (H(3)cit) by D2EHPA (H(2)A(2)) have been investigated using constant interfacial area cell with laminar flow. The stoichiometry of the complex formation reaction between La and H(2)A(2) has been evaluated. The extraction kinetics data have been analyzed in terms of pseudo-first order constants. From the effects of stirring speed, temperature and specific interfacial area on the extraction rate, it is found that the extraction process is a diffusion-controlled kinetics process with an interface reaction. The rate-determining step is made by predictions derived from interfacial reaction models, and the rate equation has been evaluated from analysis of the experimental results, also, the extraction model has been proposed. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.